Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
/*
 * The MIT License (MIT)
 *
 * Copyright (c) 2016 Lachlan Dowding
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

import java.util.concurrent.ConcurrentMap;

public class Main {
    /**
     * If the specified key is not already associated with a value, associate it with the given value.
     *
     * @param map   The map to be operated on.
     * @param key   The key with which the specified value is to be associated.
     * @param value The value to be associated with the specified key.
     * @param <K>   The class of keys in this map.
     * @param <V>   The class of values in the map.
     * @return      The previous value associated with the specified key, or null if there was no mapping for the key.
     */
    public static <K, V> V putIfAbsent(ConcurrentMap<K, V> map, K key, V value) {
        if (map == null)
            return null;
        return map.putIfAbsent(key, value);
    }
}